Elastic Protrusion Fuel Cell Unit Cell Injection Mold
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Solution Overview
Problem
Existing unit cell injection molds for fuel cells often damage the integrated membrane electrode assembly (MEA) and gas diffusion layer (GDL) inserts due to the use of metallic protrusions that prevent polymer resin from permeating, leading to increased defect rates and reduced durability of the fuel cell stack.
Innovation Solution
A unit cell injection mold featuring elastic protrusions on the upper and lower molds, made from a rubber material with higher hardness and heat resistance than protective pads, which clamp the insert to prevent polymer resin entry and minimize contact with the insert, thereby reducing damage and defects during the injection molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metallic protrusions are used to prevent polymer resin from permeating into the insert, then the resin permeation is effectively prevented, but the insert is damaged due to the hard metallic material contacting the softer insert
Solution Approach 1:
An elastic protrusion made of elastomer material is introduced as an intermediary between the metallic mold and the insert. This elastic protrusion contacts the insert during injection molding, preventing direct contact between the hard metallic mold and the soft insert, thereby preventing insert damage while still preventing resin permeation.
Solution Approach 2:
The material property of the protrusion is changed from hard metallic material to soft elastomer material. This parameter change allows the protrusion to deform elastically under injection pressure, reducing stress concentration on the insert and preventing damage while maintaining the sealing function to prevent resin permeation.
2Object-affected harmful factors
If elastic protrusions are used instead of metallic protrusions, then damage to the insert is minimized, but the ability to prevent resin permeation may be compromised
Solution Approach 1:
The elastomer material is selected with appropriate hardness and elastic modulus parameters that balance two functions: soft enough to prevent insert damage through elastic deformation, yet hard enough to maintain sealing contact and prevent resin permeation under injection pressure.
Solution Approach 2:
The elastic protrusion is designed to deform beforehand under injection pressure, absorbing the shock and stress that would otherwise be transmitted to the insert. This cushioning effect prevents insert damage while the protrusion maintains its sealing function to prevent resin permeation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of elastic protrusions effectively prevents polymer resin from entering the insert area, minimizing damage to the MEA and GDL, thus improving the marketability and durability of the fuel cell stack by reducing defects and heat transfer, and enhancing the quality of the unit cell products.
Implementation Method 1
elastic protrusions formed from an elastic material, the elastic protrusions being disposed on the upper mold and the lower mold to face each other, wherein the elastic protrusions clamp the insert to divide the inner space into the insert area and the injection area to prevent the polymer resin from entering the insert area
Data Source
AI summary
A unit cell injection mold for fabricating a unit cell of a fuel cell, in which an integrated frame of the unit cell formed by injecting a polymer resin onto an insert, in which a membrane electrode assembly and a gas diffusion layer are integrated, is formed, the unit cell injection mold includes an upper mold, a lower mold engaged with the upper mold to define an inner space between the lower mold and the upper mold, the inner space including an injection area into which the insert is accommodated and an insert area into which the polymer resin is injected to form the frame, and elastic protrusions formed from an elastic material, the elastic protrusions being disposed on the upper mold and the lower mold to face each other, wherein the elastic protrusions clamp the insert to divide the inner space into the insert area and the injection area to prevent the polymer resin from entering the insert area.